Apparatus and method for producing a gas atmosphere



March 10, 1953 A. G. HoTcHKlss APPARATUS AND METHOD FOR PRODUCING A GAS ATMOSPHERE 3 Sheets-Sheet l Filed Oct. 17, 1 947 Inventor: Allen G. Hotchkiss,

l-iis Attorney.

Marh 10, 1953 A. G. HoTcHKlss 2,631,135

APPARATUS AND METHOD FOR PRODUCING A GAS ATMOSPHERE 3 Sheets-Sheet 2 Filed Oct. 17, 1947 S, i@ y rk e om n t@ mm nn. nl M H March 10, 1953 A. G. HoTcHKlss APPARATS AND METHOD FOR PRODUCING A GAS ATMOSPHERE 3 Sheets-Sheet 3 FledOCt. 17, 1947 Inventor:

Allem G. Hotchkiss,

by His Attorney present.

Patented Mar. 10, 1953 APPARATUS AND METHOD FOR PRODUCING A GAS ATMOSPHERE Allen G. Hotchkiss, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application October 17, 1947, Serial No. 780,482

9 Claims.

My invention relates to apparatus and method for producing a gas by burning a fuel gas and thereafter purifying the gaseous products of combustion for use as a neutral, non-oxidizing, or reducing atmosphere such as in the heating of metallic articles for hardening, brazing, annealing, etc., and has for its object the combination of the burning and gas-purifying operations in such manner as to utilize the heat produced in the burning of the gas during the subsequent gas-purifying operation.

Heretofore in the manufacture of furnace gases by burning a suitable fuel gas, the combustion apparatus, such as described and claimed in my Patent No. 2,085,586, dated June 29, 1937, has been separate from the purifying apparatus by means of which the carbon dioxide gas is removed and also the small amounts of sulphur dioxide and hydrogen sulphide that may be During the burning operation, as described in my patent, the heat of combustion is removed by cooling water, this heat being wasted. Thereafter, the gaseous products of combustion are purified by passing them in contact with a suitable absorber liquid which removes the CO2 and other gases. The gas-laden absorbing liquid is then heated to a high temperature to drive olf the CO2 and H2S gases whereby the absorbing liquid is reactivated. This use oi two separate pieces of apparatus results in the waste of the heat produced during the burning of the fuel gas, additional heat being supplied to reactivate the absorbing liquid during the gas-purifying operation. v

More particularlyy in accordance with my invention I combine the burning and purifying apparatus so that the heat produced duringthe burning of the fuel gas is utilized in the heating of the absorbing liquid for the removal of the CO2 and Has gases.

For a more complete understanding of my invention reference should be had to the accompanying drawing, Fig. 1 of which is a diagrammatic representation of apparatus for producing a gas atmosphere embodying my invention, Fig. 2 is a front elevation view of apparatus for producing a gas atmosphere embodying my invention, Fig. 3 is a side elevation view of the apparatus shown in Fig. 2, Fig. 4 is a plan view of the apparatus shown in Fig. 2, Fig. 5 is an enlarged plan view of the combustion and liquid heating apparatus, Fig. 6 is a sectional view along the line 6--6 of Fig. 5 looking in the direction of the arrows, while Fig. 7 is a sectional view along the line l-l of Fig. 5 looking in the direction of the arrows.

Referring to Fig. 1 of the drawing, in carrying out my invention in one form 1 provide a combined combustion and boiler device I in which the fuel gas is burned and the heat produced utilized in boiling the CO2-absorbing liquid for the purpose of removing the CO2 and reactivating the liquid. This device is shown in detail in Figs. 5, 6 and 7. Fuel gas is supplied at a suitable pressure through a pipe 2 into the combustion chamber 3 in the device I where the gas is burned, the gaseous products of combustion, i. e. burned gas, passing downward and through a pipe 4 to a lower header 5 and then upward through heating tubes 6 to an upper header l. The combustion chamber, the pipe 4, header 5, and pipes 6 are completely surrounded by COz-absorbing liquid whereby the liquid is heated to a boiling temperature of sub-- stantially 212 degrees F. This liquid consists of a mixture of monoethanolamine and water, the percentageV of monoethanolamine being preferably from 12 to 15 by volume.

From the header 'I the hot burned gas at a temperature of approximately 300 degrees F. is passed through a pipe 8 downward through a cooler 9 wherein the gas is cooled to about 80 degrees F. From the cooler 9 the gas passes through a pipe Ill, a water separator I I in which the excess moisture condensed by the cooling.

is separated out, and then through a pipe I2 and valve I3 to a chamber i4 in the lower end of a C02 gas-absorbing tower I5. In the tower I5 which is a closed cylindrical metal tank mounted in an upright position is a quantity of ller material I6, preferably small, short porcelain tubes known as Raschig rings, through which the CO2-laden gas passes upward and by means of which the gas comes in intimate contact with the CO2-absorbing liquid supplied to the chamber I1 in the top of the tower through a pipe I8 and applied to the top of the filler material by means of a suitable spray I9. This absorbing liquid in passing downward through Vthe vfiller materiau removes substantially au of the Co2 gas from the upwardly moving gas and also the relatively small amounts of sulphur dioxide and hydrogen sulphide, the gas-laden liquid collect-l ing in the chamber I4. The gas passes out of the absorbing tower I5 through a pipe 20 downward through a cooler 2| and then through a liquid separator 22 where the liquid, water with a trace of monoethanolamine, condensed by the cooling of the gas is separated out and fed by a pipe 22 into the chamber I4. The purified gas 1s then passed through a pipe 23 to the heating chamber where it is utilized as a gas atmosphere upward through a liquid heat exchanger 26 in which it is heated by reactivated absorbing liquid supplied from the device l through a pipe 2'1A to the top of the heat exchanger and out of the bottom through pipe 29'.

laden liquid is sprayed over a mass of Raschig rings 32'.V As the liquidtrickles down over the Raschig rings, which furnish a stripping action promoting the releaselv of gases, the' liquid is heated still further bythe steam vapor arising from the quantity of boiling absorbing liquid i in the device I, theupper end of which is connected to the'lower end of the tower 36. The released CO2 and HzSV gases pass out at the top ofthe tower through a pipe 33 and then through a gas' cooler 34Y and a liquid separator 35 where the liquid condensed out bythe coolingis separated, while the'gasesescape to the'atmosphere through the pipe- 3B'. This liquid; which may contain a small amount of monoethanolamine, is returned'by a pipe 31 back to the chamber ifi.

As stated above, the reactivated hot liquid is drawn off from thev bottom of the' device i through a pipe `38 4 by means of a motor-driven pump 39 and fed through a' pipe 2T to the heat exchanger26. From the heat exchanger the liquid passesthroughf thev pipe `23 to a cooler 4d where its temperature is' reduced'to about 100 degreesA lil Theliquid is' then passed' through the pipe I8 to the absorbing tower I5' as previ` ously described'.

Referring to Figs; 6 and 7, the combustion and boiler device 'l comprises an outer cylindrical metal tankor boiler4l in which is mounted a smaller cylindrical casing or' partition 42 surroundingV the combustion'ch'amber, this casing' f 42' being adjacent one side of the tank 4f but' spaced a` shortdistance from the' wall 4i) as indicated by the' reference numeral 43', to provide for the circulation of absorbing liquid; in the' tank` 4lj'around theh combustion chamber. The' tankV 4|` is providedwithY a liquid-tight bottom wall 44 which surrounds'the casing 42. A liquidtight exteriorly removable bottom wall 45' is pro`` vided for the casing 42, this wall 45' having an inner layer of heat refractory material 46' to prevent the escape vof heat.

Inside the casing 42 isa cylindrical wall, or lining, 41 made of heat refractory material which' terminates some distance above the lower end of the casing to form a chamber 4S for the burned gas. In this chamber 48 are a plurality ofbricks 49 which are arranged in closely spaced relation so as to form supports Vfor a mass 50 of broken pieces of reY brick treated' with a suitable catalyst, such as nickel, to promote the reaction of combining the carbon with oxygen. The upper portion of the lining 4l" not filled with-the material 59 constitutes the combustion chamber 3,V which is reduced in diameten'above the lining 41. by additionalliningmembers' 52 From the heatA exchanger 26 the CO2-laden'` liquid passes and 53, the member 53 forming a throat opening 54 with which communicates a nozzle 55. The gas and air mixture feed pipe 2 is connected to this nozzle.

As the gas burns in the chamber 3, the hot gaseous -produc'tsjof combustion pass' downward into' the chamber 48 and 'from the chamber through pipe 4 to the lower cylindrical header '5 provided at the bottom with a liquid-tight connection with the bottom wall 44. It is provided with an exteriorly removable gas-tight heat insulated bottom wall 56. From the lower header 5 the gas passes upward through the vgas heat exchanger' tubes, or pipes, 6, nine being shown, to the upper` header 'l and then into the pipe' 8.

The reactivating tower 30 is secured at its lower'end to the top Wall 51 of the boiler 4i, an aperture 58 being provided in the wall 51 through which the reactivatingtower Sil' communicates with the boiler. A suitable grilli support 59 'is provided in` the'tower 3Q a short dis'- tance aboveits lower end for the Ras'chig rings 32. The CO2-free hot liquid drips from 'the' Raschig rings 32 through the opening 5S into the tank 4I. I

For-the purpose of recovering as much heat? as possible from the combustionA chamber 3,'tliel boiler 4Iv ismaintainednearly full ofY absorbing liquid at all times'so that the liquid covers almost? siderable amount of heat is transmitted to the liquid through the heat-refractory linings 4i',-

52 and 53 and the casing` 42:v The Vsize of tlie boiler 4I is so' designed with respect to the heat of combustion that the liquid in the tankis maintained at a boiling temperature or 212' de'- grees F. while, at the same time, liquid is with-y drawn through the pipe S8 for recirculation as previously described.

' To assure' at least a minimumliquid level, the' pipe 38 is extended upward inside of the boiler 4l to the upper part where it communicateswith a liquid chamber 6i]r formed by a partition wall- SI extending across'a segment-of the tank, and a segmental bottom wall 62 secured tightly to the walls of the tank. Therefore, if liquid is' withdrawn through the pipe 38 faster than -it is fed to the tank' from'the tower Sil, it will be withdrawn from' the chamber 69 andthe liquid level outside the chamber 60 maintainedlevel with thetop or the wall El at thepoint 63. Just below the openingl 58is a chute 64 which catches the liquid from the tower 3B and diverts` it-over the top of the chamber 60 into the boiler 4I.

Referring again to` Fig.V 1, the fuel gas to be`A burned is fed in through a pipe 65, a flowmeter 66, and a pipe S7 to aproportioning mixer 68 While a predetermined amount off air is fed into the mixer through a strainer 69,72. iowmeter 1D', and a pipe l2.' From the mixer 9S, which coniy prises also a gas governor for equalizing the gas i ture at a suitable pressure suchas two pounds per square inch passes through a pipe' T4', a valve 75, a fire check l5, and a valve 'V to the feed pipe V2.

In startng, the valvei' is' closed and a valve i8 is opened to allow the mixture to escape to the atmosphere until theV mixer G8 V'has beenl ad'-, justed to give the desired proportions. Then' the Valver18 is closed and the valve 11 opened. At this time a valve 19 is opened to prevent any excessive pressure in the pipe 8.

The gas is lighted by means of a lighter torch 86 which is connected through a rubber hose 8l and a valve 82 to the pipe 14. The valve B2 is opened and the gas lighted as it escapes from the end of the torch S0 constituting a burner. This end which is lighted should be heated to a redhot temperature very quickly if the gas-air proportions are correct. This heating as observed by the opeartor constitutes a check on the operation of the mixer 68. A valve 83 is now opened and the heated end of the torch 80 inserted into the combustion chamber for lighting the gas, after which the torch is removed and the valve 83 closed. A second valve 84 leads into the combustion chamber and constitutes when opened a sight opening whereby the temperature and state of combustion can be observed. The outer end of this valve is closed by a heat refractory transparent material. After the gas has been lighted, the valve 19 is closed.

The apparatus is started with a predetermined amount of the absorbing liquid in the boiler 4| and the pipes. Preferably, the valve 19 remains open until the liquid in the tank 4| is heated to a boiling temperature so that the CO2 gas will be driven 01T from any CO2-laden liquid pumped from the absorbing tower I4. Then valve 19 is closed and the pumps 25 and 39 started.

Any suitable construction can be used for the coolers 9, 2I, 34 and 4U and the heat exchanger 25. Preferably, these devices consist each of an outer cylindrical tank through which passes a vhelical coil of pipe, as disclosed in my Patent No.

2,085,587, dated June 29, 1937. In the case of the coolers, cooling water is circulated through the tank while the gas or liquid to be cooled is passed through the coil inside the tank. In the heat exchanger 26 the pipe 28 preferably leads into the coil. Cooling water is admitted through a pipe 85 to the cooler 2I and iiows from the cooler through the pipe '86, the cooler 49 and pipe 81 to the sump or drain 88. In a similar manner, cooling water is supplied through a pipe 89 to the cooler 9 and from the cooler through a pipe 99, the cooler 34 and a pipe 9| to the drain 88. Liquid from the separator Il passes through a liquid head oat trap device 92 to the drain 88, the head of liquid in the device 92 being sufficient to counterbalance the gas pressure in the pipe I0.

Preferably, enough heat is produced in the combustion chamber to maintain the absorbing liquid at a boiling temperature with the liquid pumped at full volume as long as the consumption of gas from the apparatus is over fty per cent of the maximum capacity. It will be understood that the compressor 12 maintains a constant pressure irrespective of the volume of the gas and air mixture supplied and consequently when the amount of gas taken from the pipe 23 decreases, a smaller amount of mixed air and fuel gas is supplied to the combustion chamber. When the demand decreases to fifty per cent, or below, of the maximum for the apparatus, as indicated by the flowmeters 96 and 19, a valve 93 in the pipe I8 is partly closed so as to decrease the circulation of the absorbing liquid, as indicated by a flowmeter 94. Additional checks on the operation of the apparatus are given by thermometers 95, 96 and 91, which indicate the temperature of the liquid or gas at these points.

The absorbing liquid may be replenished by means of a funnel 98 (Fig. 1) connected through a valve 99 to the pipe 24. A liquid level indicator 100 is provided on the boiler and also a pressure gauge IIlI. Also various normally closed valves are provided for use in draining and cleaning the apparatus.

The amount of air in the gas-air mixture supplied to the combustion chamber 3 may be varied to vary the completeness of combustion and thereby regulate the gaseous content of the gas supplied by the pipe 23. For most purposes, the apparatus is operated at approximately fifty per cent of complete combustion, giving a gas supply from the pipe 23 containing approximately ten to eleven per cent carbon monoxide, eighteen to twenty per cent hydrogen, and one and one-half per cent methane, the remainder being nitrogen. When the apparatus is operated at almost complete combustion, the amounts of hydrogen and carbon monoxide are low and may be less than one per cent.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An apparatus for producing a gas substantially free of carbon dioxide comprising, a boiler unit having a partition wallseparating the combustion chamber portion from the liquid chamber portion thereof, means for supplying to said combustion chamber a fuel gas mixed with an amount of air suicient to provide only partial combustion of said fuel gas, pipe means through said partition wall connecting said combustion chamber to a plurality of heat exchange tubes within said liquid chamber whereby the combusted gases produced in said combustion chamber are passed in heat exchange relationship with a carbon dioxide absorbent liquid in said liquid chamber to produce boiling thereof, a reactivating towerpositioned above said liquid chamber and arranged to discharge into said liquid chamber, a carbon dioxide absorbing device, means for passing the combusted gases from said heat exchange tubes through said absorbing device, means for passing the absorbent liquid from said boiler through said absorbing device whereby the liquid absorbs the carbon dioxide in said combusted gases, and means for transferring the carbon dioxide laden absorbent liquid from said absorbing Ydevice and inserting it into the upper portion of said reactivating tower whereby the carbon dioxide laden liquid flows downwardly in said reactivating tower into said boiler chamber and is heated by vapor from said boiler to release carbon dioxide gas.

2. Apparatus for producing a gas comprising, a boiler unit having a partition wall separating the combustion -chamber portion from the liquid chamber portion thereof, pipe means through said partition wall connecting said combustion chamber to a plurality of heat exchange tubes within said liquid chamber whereby combusted gases produced in said combustion chamber are passed: in heat exchange relationship with an absorbent liquid in said liquid chamber portion to produce` boiling thereof, a reactivating tower above said liquid chamber arranged to discharge into said liquid chamber, a gas absorbing device, means forl passing combusted gases from said heat exchangetubes through said gas absorbing device, means for passing absorbent liquid from said boiler through said gas absorbing device whereby Said liquid absorbs one of the gas components of said combusted gases, and means for transferring the absorbent liquid containing said one gas from said absorbing device and inserting it into the vupper' portion of said reactivating tower whereby l the gaslladenl liquidfiiows downwardly in saidv-reactivating tower-lintmsai'd:boiler chamber and-fis Vheated-I 'byfvaporifrom sai-d boiler-.to release..said onegae.

3. A gas producing apparatus comprising sa Yboiler unit' :having-a1 partitionwall-separatingthe conibustion chamber :portion i'from ithe iliquid cha-inbel- Aportion thereoffsthellquid'lini the liquid chamber portion vsubstantially surrounding-'said combustion chamber,==-means*forzsupplying-zcontinuouslyrto the upperportion of said-combustion 'chamber VLa; combustibles-mixture V'of fgasea pipe meansextending. through` said partition wallffrom the *lower Fportion-of saidscombustion chamber, ae-plurality 'of i heat-exchange tubes within-said "liquid chamber portion whereby the -1 combusted "gases producedin said combustion chamber'are passed` in heat exchange relationship Wit'hflan` inlcomi-ng t absorbent *liquid a reaczt-ivating `-tower positioned above said liquid chamber Iand arranged to discharge liquid-into said-liquid-cham ber, an absorbing towen-conduitmeans' `for transferring saidv combusted-gases fromesad heat-fox- Achange tubes and-'passing them `upwardly' through said absorbing touren-means fortransferringfsa-id -absorbent.v liquid from said boiler and-passing it downwardly through said absorbing tower wherelby said liquid 4absorbs one gaseouscomponent of saidlcombuste'd gases; aridY means for transferring thegas laden absorbentdiquid*fromfthelbottom 'of 4said absorbingi tower' andpassi-ng' itl into* the upper portion-ot' said reactivating tower--whereby the gas laden absorbent liquid' ows downwardly irl-said reactivating tower `intqsaid boilerchamber and Ais heated-byvapor-from said boiler to're- Ilease said one gaseouscomponent.

- 4. An apparatuslfor producing "a-gas substantially free of carbon dioxidecomprising a boiler f unitI having a' l.partition wall:separating the-com Ybustion chamber-*portion thereof from'theliquid f chamber portion, theliquid in :said liquid' chamber:l portion substantially surroundingsaid'-com bustionchamber portion, l means for supplying 1 continuouslyto the uppelI portion off'sa-id-fcombustion chamber a hydrocarbon gas-mixed vwith an lamrnount ofiair suicienttoV provide-only-par- I. tial combustion of 'said F hydrocarbon 4igas, pipe means connecting'thelowerfportion ofsaid-combustion chamber tola plurality fof f heat` exchange tubes Within-said liquid chamber. -portionlwhereby thecon'ibuste'd; gasesV Vproduced' .saidfcomf-bustion chamberare passed Lin heat exchange relationship with a carbon dioxide :absorbent f liquid in the liquid .chambers aireactivatingf, tower positioned v.above said '.liquid chamber sand larn ranged to discharge into saidliquidhamberga carbon dioxide absorbing device, means forr transerring' said. .combusted .-gases: from said: heatv .exchangev tubesfand .passing them..through;-said ab sorbent liquid from said Vboiler-fand f passing .it :through said absorbing devicewherebysaid liquid .absorbsthecarbon .dioxide in said rconibusted gases, .and meansi for transferring:l the absorbing i liquid:V containingY .carbondioxidefrom :said --abs sorbing .device :land passing the :heated .'carbon .f dioxidaladen absorbenty liquid into the Vupper-spor- `.tion of said `reactivating .tower svherebyl-such liquid t flows downwardly .in -said reactivating tower into .said .boiler :chamber .andis heatedy .by .vapor V.from said ';-;boiler tito :release .carbon .-dioxide..gas.

5. 'An apparatus'ior:.producingagasfconsisting 4:mainly of nitrogen and containingzsubstantial :amounts .of-carbon monoxideandmydrogembut substantially.ffree iof car-bon A:dioxide comprising, an enclosed :boiler e, unit having a :combustion chamber portion. separa-ted abyfa; partition 'from .aliquid.chamberr portion, theL liquid in said.` liquid ,I5 chamber. portion :substantially surrounding a'said combustion ichamber fportion, means: for supplying .1 continuously :to i the i upper y portion of said combustion chamber :a L hydrocarbon -gas ,mixed withsaniainount of air suilicient toprovide only 10 partial combustion .10i i said hydrocarbon gas, fra .plurality of heat exchange tubes in verticallydis posedrelationawithin said liquid chan1ber.afdis .charge :pipe .extending through .':said partition -waikandifconnccting the lower portion-of said .15 'combustionfchamber1to 4said tubeswhereby the A:cornbusted gases produced in :said combustion chamberiare passed in heat-exchange relationship .fwith :an incoming carbon 'dioxide @absorbent liquid,-.a reactivating towerpositioned: in vertical- ,20 ly disposed*relationfabove said` boiler and'dis- `charging vdirectly =.into .said 'liquid chamber .throughzran'openingin thetop thereof, a vertically disposed carbon dioxide absorbing tower, means :for gtranserring said combusted :gases from said` heatexchangeptubes and passing them Yupwardly through 'said absorbing 1. tower, means for: transferring .said absorbent liquidjfrom .said 4boiler -andpassingfit downwardly through said :absorbinggtower whereby said1 liquid'4 absorbs the :carbon :dioxide in` said. combusted-gases, outlet means for .the .carbon 'dioxide free-gas connected :toi said absorbing* towen. means, for transferring Vtheicarbon dioxide laden-absorbing liquid from the `lfiottoni-.of said., absorbing tower fand passing .'itrdownwardly through sai'dfreactivating tower .whereby such.' liquid` flows through said reactivat- "ing, tower and ris dischargedzinto said liquid chamber, said carbon :dioxide 1 laden absorbent liquid being-heated. byvapcr. ronrsaid boiler to release fithefcarbon"dioxide.-.gas,` and outlet. means for re- :m'oving the carbon dioxide -gas .ffromv said re- Y activating chamber.

1,6. eAegasburning. and purifying .apparatus for .producing .a gas consisting mainly of hydrogen u .and.:containing .substantial amountsof carbon fmonoxide and hydrogen vbut:substantially free '.of .carbon dioxide, Ycomprising enclosed boiler ,uniti having` thereina: cylindrical wallforming a :combustion A'chamber' 'rnounted -in vertically fdis- .posedz relation in position tube substantially.;sur

:rounded byarliquidi in said boiler, a heatirefrac- .toryf lining .zwithinfisaid cylindrical wall, a: quantityof; pieces of refractory material. within. said fractory. lining treatedzwith ,a catalyst material 5 t vpromotev the; combination'off carbonwith `oxyregen,h support .-rneanslfor said catalyst material v@near f the :bottom -of .fsaid :combustion chamber, means forsupplying .to the top .of-said` combus- .;tionichamber.a fuel .gas under predetermined Lil) `sorbing` device,Y means forstransierringfzsaid -fabtoo "lf/fessure ancl'llflx'dA Wilma :predetermined amount l. of: air; .suilcient to provide. vonlye partial combus- 'tion vin said` combustion chamber, Vadischarge zpipe opening .below :said support. means extend- -ing1throughithevzsai`d cylindrical wall,'a plurality 55 -ofyertically disposedheatexchange tubes .within f the l liquid chamber .portion of said; .boiler unit, :rsa-id pipe being connected nto thelowerfend of said tubes :wherebypthe .burned gases produced in: said -combustion. chamber. are. passed in heat 70 exchange Vrelationship yivithlza; carbon dioxide .ab-

.sorbent'liquidcomprisingfa mixture. of Vmonosethanolamine "and water, :..a freactivating tower having a mass of llerfmaterial` thereinlmounted on :sa-id #boiler :above ,.fsaid liquid chamber and 15g-arranged :to :discharge ,liquid finto `.said :liquid 9 chamber through an'opening in the top thereof, the heat from the burned gases passing through said heat exchanger tubes heating the liquid in said liquid chamber to a boiling temperature whereby the steam therefrom passes upwardly through said filler material in said reactivating tower, a first gas cooler, a gas absorbing tower containing a mass of filler material and provided with a liquid collecting Achamber below said .ller material, means for passing the burned gases from said heat exchanger tubes in the boiler chamber through said first gas cooler and then upwardly through said filler material in said absorbing tower, a liquid heat exchanger, a liquid cooler, duct and pump means for continuously passing liquid at a predetermined rate from the bottom of said liquid chamber through said liquid heat exchanger and then through said liquid cooler and into the upper end of said absorbing tower whereby the liquid fiows downwardly over said ller material absorbing carbon dioxide from said burned gases and collecting in said liquid collecting chamber, duct means for conveying the purified gas from the upper end of said absorbing tower, duct and pump means for pass- ,f

ing the carbon dioxide laden liquid from said liquid collecting chamber through said liquid heat exchanger where it is heated by the hot liquid passing therethrough from the boiler to the absorbing tower and then passing said carbon dioxide laden liquid into the top of said reactivating tower whereby said liquid flows downwardly over the filler material in said tower into said boiler chamber and is heated by said steam from said boiler to release carbon dioxide gas, a second gas cooler, duct means for passing carbon dioxide gas from the top of said reactivating tower through said second gas cooler to the outside atmosphere, and duct means for returning to said liquid collecting chamber liquid condensed from said carbon dioxide gas in said second cooler.

'7. The process of producing a gas substantially free from carbon dioxide which comprises, supplying a mixture of a fuel gas and air suilicient to provide only partial combustion of said fuel gas to a jacketed combustion chamber enclosed within a boiler unit, burning said mixture in said combustion chamber, removing the combusted gases from said combustion chamber and passing them through a plurality of heat exchange tubes in the liquid chamber portion of said boiler unit whereby heat is transferred to a carbon dioxide absorbent liquid in said chamber, this heat producing boiling of said liquid whereby vapor is given off, removing said combusted gases from said heat exchanger tubes and passing them through an absorbing device, removing said liquid from said liquid chamber and passing it through said absorbing device whereby it absorbs substantially all of the carbon dioxide in said combusted gases, and removing the carbon dioxide laden absorbent liquid from said absorbing device and introducing it into a reactivating tower above the boiler whereby it passes downwardly through said reactivating tower and is discharged into said liquid chamber, said carbon dioxide being released from the absorbent liquid in said reactivating tower by the action of said vapor from said liquid chamber.

8. The process of producing a gas substantially free from carbon dioxide which comprises, supplying a mixture of fuel gas and air sumcient to provide only partial combustion of said fuel gas to a jacketed combustion chamber having an internal lining of heat refractory material and i enclosed within a boiler unit, burning said mixture in said combustion chamber in the presence of a catalyst, removing the combusted gases from the bottom of said combustion chamber and passing them upwardly through a plurality of heat exchange tubes in the liquid chamber portion of said boiler unit whereby heat is transferred to a carbon dioxide absorbent liquid in said chamber, said heat producing boiling of said liquid wherebyvapor is given off, removing said combusted gases from the heat exchanger tubes and passing them upwardly through an absorbing tower, removing said liquid from the bottom of said boiler chamber and passing it through a liquid heat exchanger, thereafter passing the liquid from the boiler chamber downwardly through said absorbing tower whereby it absorbs substantially all of the carbon dioxide in said combusted gases, removing the carbon dioxide laden absorbent liquid from the bottom of said absorbing tower and p-assing it through said heat exchanger whereby it absorbs some of the heat from the liquid passing from said boiler to said absorbing tower, and thereafter introducing the carbon dioxide laden liquid into a reactivating tower above the boiler whereby it passes downwardly through said reactivating tower and is discharged into said liquid chamber, carbon dioxide being released from said absorbent liquid in said reactivating tower by the action of said vapor from the liquid chamber.

9. The process of producing a gas consisting mainly of nitrogen and containing substantial amounts of carbon monoxide and hydrogen but substantially free of carbon dioxide which comprises, supplying a fuel gas under predetermined pressure and mixed with a predetermined amount of air sufficient to provide only partial combustion to the upper portion of a metal jacketed combustion chamber having an internal refractory lining and enclosed within a boiler unit, burning said mixture in said combustion chamber in the presence of a quantity of pieces of refractory material treated with a catalyst material to promote the combination of carbon with oxygen, removing the combusted gases from the bottom of said combustion chamber and passing them upwardly through a plurality of vertically disposed heat exchanger tubes in the liquid chamber portion of said boiler unit whereby a portion of the heat contained in said combusted gases is transferred to a carbon dioxide absorbent liquid in said chamber comprising a mixture of monoethanolamine and water producing boiling of said liquid and giving oif steam, removing said combusted gases from said heat exchanger tubes and passing them through a cooler and thereafter passing them upwardly through an absorbing tower containing a mass of filler material, removing said liquid from the bottom of said boiler chamber and passing it through a liquid heat exchanger and a liquid cooler and thereafter passing it downwardly through said absorbing tower over the filler material therein whereby it absorbs substantially all of the carbon dioxide in said combusted gases, removing the purified combusted gases from the top of said absorbing towever, removing the carbon dioxide laden absorbent liquid from the bottom of said absorbing tower and passing it through said liquid heat exchanger whereby it absorbs a portion of the heat from the liquid being transferred from the boiler chamber to the absorbing tower, thereafter introducing said carbon dioxide laden liquid into the top of a reactivating tower having a 1 l l2 mass of filler material therein located aboveA said REFERENCES CITED boiler whereby such liquid passes downwardly The following references are., of record in the through said reactivating tower and is discharged me of this patent:

into said liquid chamber, carbon dioxide being released from the absorbent liquid by the action 5 UNITED STATES PATENTS of said steam from said liquid chamber, removing i Numberr Name Date saldreleased carbon dloxldefromsaid reactivatf ingr. chamber and cooling it to reclaim absorbent T3536 Kpwlles Juy 5 1910 liquid therefrom, and returning such reclaimed 11..'637323 iedel g1g 192 liquid to the bottom of said absorbingtower'. m 2'314'827. Hertet "Maf '23" 1943 ALLEN G. HOTCHKISS. 

1. AN APPARATUS FOR PRODUCING A GAS SUBSTANTIALLY FREE OF CARBON DIOXIDE COMPRISING, A BOILER UNIT HAVING A PARTITION WALL SEPARATING THE COMBUSTION CHAMBER PORTION FROM THE LIQUID CHAMBER PORTION THEREOF, MEANS FOR SUPPLYING TO SAID COMBUSTION CHAMBER A FUEL GAS MIXED WITH AN AMOUNT OF AIR SUFFICIENT TO PROVIDE ONLY PARTIAL COMBUSTION OF SAID FUEL GAS, PIPE MEANS THROUGH SAID PARTITION WALL CONNECTING SAID COMBUSTION CHAMBER TO A PLURALITY OF HEAT EXCHANGE TUBES WITHIN SAID LIQUID CHAMBER WHEREBY THE COMBUSTED GASES PRODUCED IN SAID COMBUSTION CHAMBER ARE PASSED IN HEAT EXCHANGE RELATIONSHIP WITH A CARBON DIOXIDE ABSORBENT LIQUID IN SAID LIQUID CHAMBER TO PRODUCE BOILING THEREOF, A REACTIVATING LOWER POSITIONED ABOVE SAID LIQUID CHAMBER AND ARRANGED TO DISCHARGE INTO SAID LIQUID CHAMBER, A CARBON DIOXIDE ABSORBING DEVICE, MEANS FOR PASSING THE COMBUSTED GASES FROM SAID HEAT EXCHANGE TUBES THROUGH SAID ABSORBING DEVICE, MEANS FOR PASSING THE ABSORBENT LIQUID FROM SAID BOILER THROUGH SAID ABSORBING DEVICE WHEREBY THE LIQUID ABSORBS THE CARBON DIOXIDE IN SAID COMBUSTED GASES, AND MEANS FOR TRANSFERRING THE CARBON DIOXIDE LADEN ABSORBENT LIQUID FROM SAID ABSORBING DEVICE AND INSERTING IT INTO THE UPPER PORTION OF SAID REACTIVATING TOWER WHEREBY THE CARBON DIOXIDE LADEN LIQUID FLOWS DOWNWARDLY IN SAID REACTIVATING TOWER INTO SAID BOILER CHAMBER AND IS HEATED BY VAPOR FROM SAID BOILER TO RELEASE CARBON DIOXIDE GAS.
 9. THE PROCESS OF PRODUCING A GAS CONSISTING MAINLY OF NITROGEN AND CONTAINING SUBSTANTIAL AMOUNTS OF CARBON MONOXIDE AND HYDROGEN BUT SUBSTANTIALLY FREE OF CARBON DIOXIDE WHICH COMPRISES, SUPPLYING A FUEL GAS UNDER PREDETERMINED PRESSURE AND MIXED WITH A PREDETERMINED AMOUNT OF AIR SUFFICIENT TO PROVIDE ONLY PARTIAL COMBUSTION TO THE UPPER PORTION OF A METAL JACKETED COMBUSTION CHAMBER HAVING AN INTERNAL REFRACTORY LINING AND ENCLOSED WITHIN A BOILER UNIT, BURNING SAID MIXTURE IN SAID COMBUSTION CHAMBER IN THE PRESENCE OF A QUANTITY OF PIECES OF REFRACTORY MATERIAL TREATED WITH A CATALYST MATERIAL TO PROMOTE THE COMBINATION OF CARBON WITH OXYGEN, REMOVING THE COMBUSTED GASES FROM THE BOTTOM OF SAID COMBUSTION CHAMBER AND PASSING THEM UPWARDLY THROUGH A PLURALITY OF VERTICALLY DISPOSED HEAT EXCHANGER TUBES IN THE LIQUID CHAMBER PORTION OF SAID BOILER UNIT WHEREBY A PORTION OF THE HEAT CONTAINED IN SAID COMBUSTED GASES IS TRANSFERRED TO A CARBON DIOXIDE ABSORBENT LIQUID IN SAID CHAMBER COMPRISING A MIXTURE OF MONOETHANOLAMINE AND WATER PRODUCING BOILING OF SAID LIQUID AND GIVING OFF STEAM, REMOVING SAID COMBUSTED GASES FROM SAID HEAT EXCHANGER TUBES AND PASSING THEM THROUGH A COOLER AND THEREAFTER PASSING THEM UPWARDLY THROUGH AN ABOSRBING TOWER CONTAINING A MASS OF FILTER MATERIAL, REMOVING SAID LIQUID FROM THE BOTTOM OF SAID BOILER CHAMBER AND PASSING IT THROUGH A LIQUID HEAT EXCHANGER AND A LIQUID COOLER AND THEREAFTER PASSING IT DOWNWARDLY THROUGH SAID ABSORBING TOWER OVER THE FILLER MATERIAL THEREIN WHEREBY IT ABSORBS SUBSTANTIALLY ALL OF THE CARBON DIOXIDE IN SAID COMBUSTED GASES, REMOVING THE PURIFIED COMBUSTED GASES FROM THE TOP OF SAID ABSORBING TOWEVER, REMOVING THE CARBON DIOXIDE LADEN ABSORBENT LIQUID FROM THE BOTTOM OF SAID ABSORBING TOWER AND PASSING IT THROUGH SAID LIQUID HEAT EXCHANGER WHEREBY IT ABSORBS A PORTION OF THE HEAT FROM THE LIQUID BEING TRANSFERRED FROM THE BOILER CHAMBER TO THE ABSORBING TOWER, THEREAFTER INTRODUCING SAID CARBON DIOXIDE LADEN LIQUID INTO THE TOP OF A REACTIVATING TOWER HAVING A MASS OF FILTER MATERIAL THEREIN LOCATED ABOVE SAID BOILER WHEREBY SUCH LIQUID PASSES DOWNWARDLY THROUGH SAID REACTIVATING TOWER AND IS DISCHARGED INTO SAID LIQUID CHAMBER, CARBON DIOXIDE BEING RELEASED FROM THE ABSORBENT LIQUID BY THE ACTION OF SAID STEAM FROM SAID LIQUID CHAMBER, REMOVING SAID RELEASED CARBON DIOXIDE FROM SAID REACTIVATING CHAMBER AND COOLING IT TO RECLAIM ABSORBENT LIQUID THEREFROM, AND RETURNING SUCH RECLAIMED LIQUID TO THE BOTTOM OF SAID ABSORBING TOWER. 